The prospect of female-only conception is getting closer, leaving aside the science fiction movies.
Soon, women could produce sperm of their own, a technology that could permit lesbian couples to deliver their own biological offspring.
After scientists managed to produce predecessors of sperm cells from male bone marrow tissue, they are seeking for a possibility to produce sperm cells from a woman's bone marrow tissue.
The previous research was aimed at restoring fertility to men, enabling them to produce fertile sperm. "But the results also raise the prospect of taking bone-marrow tissue from women and coaxing the stem cells within the female tissue to develop into sperm cells," said Professor Karim Nayernia of the University of Newcastle upon Tyne.
In this case, the lesbian couples would have only daughters as women lack the Y chromosome found in half of the male sperm cells that induce the male sex in embryos. "Theoretically it is possible. The problem is whether the sperm cells are functional or not. I don't think there is an ethical barrier so long as it's safe. We are in the process of applying for ethical approval. We are preparing now to apply to use the existing bone marrow stem cell bank here in Newcastle", Nayernia said.
If this proves viable, sperm cells from female bone tissue will be grown in the lab and their ability to penetrate into a hamster's egg (a standard fertility test for sperm) could be easy to check. "But there is no intention at this stage to produce female sperm that would be used to fertilize a human egg, which would require the approval of the Human Fertilization and Embryology Authority," said Nayernia.
"The ultimate aim is to see whether these secondary stem cells can then be made into other useful tissues of the body. Our next goal is to see if we can get the spermatagonial stem cells (that transform into sperm cells) to progress to mature sperm in the laboratory and this should take around three to five years of experiments", he said.
In 2006, Nayernia led a team at the University of Gottingen in Germany who, for the first time, achieved viable sperm from mouse stem cells, sperm that produced seven healthy offspring.